(1) Field of the Invention
The present invention relates to bridges and related structures and more particularly to gangways, ramps and dock levelers. Still more particularly this invention relates to portable, lightweight and modular ramps.
(2) Brief Description of the Prior Art
To address the needs of human access (such as for handicapped people) or general physical access, building owners have been required to construct accessibility structures for their buildings. These structures typically are fixed and made of concrete, steel or wood decking and hand metal rails. The installation of these structures, as required by law or building codes, can be expensive and at times geometrically impossible, as in the case of some historical buildings, which are unalterable by historical preservation laws or standards.
The prior art discloses various ramps and similar structures, which include features that are intended to facilitate their rapid and relatively inexpensive construction.
U.S. Pat. No. 3,301,149 to Box, for example, discloses a portable deck in which each mat has tongues and grooves for mating with adjacent mats. Holes in these tongues align with holes in the grooves. A pin passes through aligned holes to hold the mats together.
U.S. Pat. No. 3,546,773 to Gerstin discloses a modular structure made of polymer foam blocks held together with cables passing therethrough.
U.S. Pat. No. 4,807,317 to Quinn et al. discloses a modular and reusable wheelchair ramp capable of ready assembly and disassembly while providing a strong and safe construction. The ramp includes a plurality of leg assemblies fabricated of PVC plumbing components and a plurality of ramp sections each extending between and mounted on a pair of adjacent leg assemblies. Each leg assembly includes a pair of legs and an interconnecting crossbar slidably received thereon for ready height adjustability. The ramp sections are hooked over the crossbars. Handrails also fabricated of PVC plumbing components are also slidably mounted on the legs.
U.S. Pat. No. 5,214,817 to Allen discloses a modular ramp and landing assembly made from a plurality of similarly sized pre-manufactured concrete filled rectangular panels. The ramp portion is made from the modular panels attached by their shorter sides. A support post with an angularly arranged bracket is placed beneath the corners of adjacent panels to secure them together as well as support them. The landing or horizontal portion of this assembly comprises a similarly sized rectangular panel the long side of which is in abutting relationship with the short side of the end of the ramp. Fastener receivers are equi-spaced in duplicate patterns from each corner through the bottom edge of each panel. The size of the panels and the spacing of the fastener receivers are such that minimum support legs and brackets may be utilized in constructing this assembly at a final site.
U.S. Pat. No. 5,341,533 to Seitz discloses a modular ramp that comprises multiple sections that, except for height, have a similar cross-section and length along the ramp. Each modular section has a groove on one edge and a lip on the opposed edge that engage mating features of the preceding and following sections. The modular sections are conveniently prefabricated and provided in kit form to the number of sections corresponding to the desired ramp height.
U.S. Pat. No. 5,457,837 to Zuckerbrod discloses a portable track device for a wheelchair that includes at least two track sections, which can be coupled removably to each other, and each track section has a bottom channel between a right sidewall and a left sidewall, with a reinforcement rod in each sidewall and with transverse supports located in the bottom channel. Each track section is equal to, or greater than the length of the wheelchair. The occupant of the wheelchair can travel safely across difficult terrain, such as a sandy beach.
U.S. Pat. No. 5,446,937 to Haskins discloses a modular ramp system in which each section is sloped owing to its leg height. The elements may be arranged in various combinations in order to conform to thresholds having offsets of different heights.
A need still exists, however, for improved means of providing a ramp where there are disadvantages to the expensive and time-consuming construction of a permanent ramp.
It is an object of the present invention to provide a portable lightweight ramp which can be used to assist handicapped people at public or other buildings where the alteration of the building into a permanent accessible structure is not permitted or desirable due to economic, geometric, geographic or historical constraints. Such a ramp can have wide application, for example, at military and naval installations as a portable, convenient, expedient and inexpensive way to load and unload buildings and ships.
The ramp of the present invention includes a plurality of interconnecting panels. A first panel has a proximate end and a distal end. At the proximate end there is detachable means for connecting the first panel to a step, curb, threshold or other obstruction the ramp is to be used to provide access to. A second panel has a proximate and distal end and at the proximate end there is a detachable means for connecting the second panel to the distal end of said first panel. This modular ramp is adapted to be lightweight and portable.
Preferably, this portable ramp will have a rigid polyethylene skin, impregnated with a polymeric foam core. The ramp will consist of a main panel section, a male tongue and female slots with two slots and two holes on two sides. During assembly, there will be a main slot with two holes for interlocking. The slots will interlock with mating parts and be pinned securely. There will be added accessories such as handrails, support legs and end caps, all of which will be installed in the slots and pinned.